vir·tu·al / ˈvərchoōəl/ • adj. almost or nearly as described, but not completely or according to strict definition: the virtual absence of border controls. ∎ Comput. not physically existing as such but made by software to appear to do so: a virtual computer. See also virtual reality. ∎ Optics relating to the points at which rays would meet if produced backward. ∎ Physics denoting particles or interactions with extremely short lifetimes and (owing to the uncertainty principle) indefinitely great energies, postulated as intermediates in some processes.DERIVATIVES: vir·tu·al·i·ty / ˌvərchoōˈalitē/ n.